2021 RETA Breeze Nov/Dec

read at least 432 psig. Likely candidates would be gauges reading 450 or 500 psig. In Yuma, AZ, where the 1%Wet Bulb Temperature is 78.1°F, the design pressure must be no less than the saturation pressure corresponding to 30°F above the 1%WB temperature, assuming an evaporatively cooled system. Therefore, the minimum design pressure for this system would be 250 psig, since the corresponding pressure for a saturation temperature of 108.1°F is 225 psig. This would require gauges on the high side that read at least 300 psig. As stated in my last column, the takeaway is if you are using pressure gauges on the high side of your system, be mindful of the system design pressure. Now that I have addressed my Epic Failure, it is time to move on to this month’s column. In the first photo, we see a gauge panel that the operators use for monitoring their system pressures. In fact, it may

not be unlike the one that you use at your facility. When we look to the second photo, we see one of the small bore tubing lines that runs from the machinery room to this gauge panel, which happens to be outside of the machinery room. The other lines are run in a similar manner. So where exactly do these lines run? As it turns out, they run through the room in which the maintenance department‘s PLC programmer works. First, it is lacking any sort of piping labels. This means that it does not comply with IIAR2-2021, Section 5.14.6, which states “Ammonia piping mains, headers, and branches shall be identified with the flowing information: 1. ‘AMMONIA’; 2. Physical state of ammonia; So how does this fail? Let me count the ways.

3. Relative pressure level of ammonia, being low or high, as applicable; 4. Pipe service, which shall be permitted to be abbreviated; and 5. Direction of flow. The marking system shall be either one established by a recognized model code or standard or one described and documented by the facility owner or the owner’s agent.” Second, you can see the compression fitting at the end of the tubing where it joins with the valve. This does not comply with IIAR2-2021, Section 13.2.3.1.1, which states “Carbon steel tubing and carbon steel compression fittings shall be limited to valve sensing pilots, compressors, compressor packages, and packaged systems.” Third, while you can’t see them in these photos, there are in-line compression couplers connected multiple sections of tubing together. This then creates a requirement for ammonia detection in

RETA.com 9